subversion/libsvn_fs_fs/dag.h

   1 /* dag.h : DAG-like interface filesystem, private to libsvn_fs
   2  *
   3  * ====================================================================
   4  * Copyright (c) 2000-2006 CollabNet.  All rights reserved.
   5  *
   6  * This software is licensed as described in the file COPYING, which
   7  * you should have received as part of this distribution.  The terms
   8  * are also available at http://subversion.tigris.org/license-1.html.
   9  * If newer versions of this license are posted there, you may use a
  10  * newer version instead, at your option.
  11  *
  12  * This software consists of voluntary contributions made by many
  13  * individuals.  For exact contribution history, see the revision
  14  * history and logs, available at http://subversion.tigris.org/.
  15  * ====================================================================
  16  */
  17
  18 #ifndef SVN_LIBSVN_FS_DAG_H
  19 #define SVN_LIBSVN_FS_DAG_H
  20
  21 #include "svn_fs.h"
  22 #include "svn_delta.h"
  23
  24 #include "fs.h"
  25
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif /* __cplusplus */
  29
  30 \f
  31 /* The interface in this file provides all the essential filesystem
  32    operations, but exposes the filesystem's DAG structure.  This makes
  33    it simpler to implement than the public interface, since a client
  34    of this interface has to understand and cope with shared structure
  35    directly as it appears in the database.  However, it's still a
  36    self-consistent set of invariants to maintain, making it
  37    (hopefully) a useful interface boundary.
  38
  39    In other words:
  40
  41    - The dag_node_t interface exposes the internal DAG structure of
  42      the filesystem, while the svn_fs.h interface does any cloning
  43      necessary to make the filesystem look like a tree.
  44
  45    - The dag_node_t interface exposes the existence of copy nodes,
  46      whereas the svn_fs.h handles them transparently.
  47
  48    - dag_node_t's must be explicitly cloned, whereas the svn_fs.h
  49      operations make clones implicitly.
  50
  51    - Callers of the dag_node_t interface use Berkeley DB transactions
  52      to ensure consistency between operations, while callers of the
  53      svn_fs.h interface use Subversion transactions.  */
  54
  55 \f
  56 /* Generic DAG node stuff.  */
  57
  58
  59 /* Fill *NODE with a dag_node_t representing node revision ID in FS,
  60    allocating in POOL.  */
  61 svn_error_t *
  62 svn_fs_fs__dag_get_node(dag_node_t **node,
  63                         svn_fs_t *fs,
  64                         const svn_fs_id_t *id,
  65                         apr_pool_t *pool);
  66
  67
  68 /* Return a new dag_node_t object referring to the same node as NODE,
  69    allocated in POOL.  If you're trying to build a structure in a
  70    pool that wants to refer to dag nodes that may have been allocated
  71    elsewhere, you can call this function and avoid inter-pool pointers. */
  72 dag_node_t *svn_fs_fs__dag_dup(dag_node_t *node,
  73                                apr_pool_t *pool);
  74
  75
  76 /* Return the filesystem containing NODE.  */
  77 svn_fs_t *svn_fs_fs__dag_get_fs(dag_node_t *node);
  78
  79
  80 /* Set *REV to NODE's revision number, allocating in POOL.  If NODE
  81    has never been committed as part of a revision, set *REV to
  82    SVN_INVALID_REVNUM.  */
  83 svn_error_t *svn_fs_fs__dag_get_revision(svn_revnum_t *rev,
  84                                          dag_node_t *node,
  85                                          apr_pool_t *pool);
  86
  87
  88 /* Return the node revision ID of NODE.  The value returned is shared
  89    with NODE, and will be deallocated when NODE is.  */
  90 const svn_fs_id_t *svn_fs_fs__dag_get_id(dag_node_t *node);
  91
  92
  93 /* Return the created path of NODE.  The value returned is shared
  94    with NODE, and will be deallocated when NODE is.  */
  95 const char *svn_fs_fs__dag_get_created_path(dag_node_t *node);
  96
  97
  98 /* Set *ID_P to the node revision ID of NODE's immediate predecessor,
  99    or NULL if NODE has no predecessor, allocating from POOL. */
 100 svn_error_t *svn_fs_fs__dag_get_predecessor_id(const svn_fs_id_t **id_p,
 101                                                dag_node_t *node,
 102                                                apr_pool_t *pool);
 103
 104
 105 /* Set *COUNT to the number of predecessors NODE has (recursively), or
 106    -1 if not known, allocating from POOL.  */
 107 svn_error_t *svn_fs_fs__dag_get_predecessor_count(int *count,
 108                                                   dag_node_t *node,
 109                                                   apr_pool_t *pool);
 110
 111 /* Set *COUNT to the number of node under NODE (inclusive) with
 112    svn:mergeinfo properties, allocating from POOL.  */
 113 svn_error_t *svn_fs_fs__dag_get_mergeinfo_count(apr_int64_t *count,
 114                                                 dag_node_t *node,
 115                                                 apr_pool_t *pool);
 116
 117 /* Set *DO_THEY to a flag indicating whether or not NODE is a
 118    directory with at least one descendant (not including itself) with
 119    svn:mergeinfo. */
 120 svn_error_t *
 121 svn_fs_fs__dag_has_descendants_with_mergeinfo(svn_boolean_t *do_they,
 122                                               dag_node_t *node,
 123                                               apr_pool_t *pool);
 124
 125 /* Set *HAS_MERGEINFO to a flag indicating whether or not NODE itself
 126    has svn:mergeinfo set on it. */
 127 svn_error_t *
 128 svn_fs_fs__dag_has_mergeinfo(svn_boolean_t *has_mergeinfo,
 129                              dag_node_t *node,
 130                              apr_pool_t *pool);
 131
 132 /* Return non-zero IFF NODE is currently mutable. */
 133 svn_boolean_t svn_fs_fs__dag_check_mutable(dag_node_t *node);
 134
 135 /* Return the node kind of NODE. */
 136 svn_node_kind_t svn_fs_fs__dag_node_kind(dag_node_t *node);
 137
 138 /* Set *PROPLIST_P to a PROPLIST hash representing the entire property
 139    list of NODE, allocating from POOL.  The hash has const char *
 140    names (the property names) and svn_string_t * values (the property
 141    values).
 142
 143    If properties do not exist on NODE, *PROPLIST_P will be set to
 144    NULL. */
 145 svn_error_t *svn_fs_fs__dag_get_proplist(apr_hash_t **proplist_p,
 146                                          dag_node_t *node,
 147                                          apr_pool_t *pool);
 148
 149 /* Set the property list of NODE to PROPLIST, allocating from POOL.
 150    The node being changed must be mutable.  */
 151 svn_error_t *svn_fs_fs__dag_set_proplist(dag_node_t *node,
 152                                          apr_hash_t *proplist,
 153                                          apr_pool_t *pool);
 154
 155 /* Increment the mergeinfo_count field on NODE by INCREMENT.  The node
 156    being changed must be mutable.  */
 157 svn_error_t *svn_fs_fs__dag_increment_mergeinfo_count(dag_node_t *node,
 158                                                       apr_int64_t increment,
 159                                                       apr_pool_t *pool);
 160
 161 /* Set the has-mergeinfo flag on NODE to HAS_MERGEINFO.  The node
 162    being changed must be mutable.  */
 163 svn_error_t *svn_fs_fs__dag_set_has_mergeinfo(dag_node_t *node,
 164                                               svn_boolean_t has_mergeinfo,
 165                                               apr_pool_t *pool);
 166
 167
 168 \f
 169 /* Revision and transaction roots.  */
 170
 171
 172 /* Open the root of revision REV of filesystem FS, allocating from
 173    POOL.  Set *NODE_P to the new node.  */
 174 svn_error_t *svn_fs_fs__dag_revision_root(dag_node_t **node_p,
 175                                           svn_fs_t *fs,
 176                                           svn_revnum_t rev,
 177                                           apr_pool_t *pool);
 178
 179
 180 /* Set *NODE_P to the root of transaction TXN_ID in FS, allocating
 181    from POOL.
 182
 183    Note that the root node of TXN_ID is not necessarily mutable.  If
 184    no changes have been made in the transaction, then it may share its
 185    root directory with its base revision.  To get a mutable root node
 186    for a transaction, call svn_fs_fs__dag_clone_root.  */
 187 svn_error_t *svn_fs_fs__dag_txn_root(dag_node_t **node_p,
 188                                      svn_fs_t *fs,
 189                                      const char *txn_id,
 190                                      apr_pool_t *pool);
 191
 192
 193 /* Set *NODE_P to the base root of transaction TXN_ID in FS,
 194    allocating from POOL.  Allocate the node in TRAIL->pool.  */
 195 svn_error_t *svn_fs_fs__dag_txn_base_root(dag_node_t **node_p,
 196                                           svn_fs_t *fs,
 197                                           const char *txn_id,
 198                                           apr_pool_t *pool);
 199
 200
 201 /* Clone the root directory of TXN_ID in FS, and update the
 202    `transactions' table entry to point to it, unless this has been
 203    done already.  In either case, set *ROOT_P to a reference to the
 204    root directory clone.  Allocate *ROOT_P in POOL.  */
 205 svn_error_t *svn_fs_fs__dag_clone_root(dag_node_t **root_p,
 206                                        svn_fs_t *fs,
 207                                        const char *txn_id,
 208                                        apr_pool_t *pool);
 209
 210
 211 \f
 212 /* Directories.  */
 213
 214
 215 /* Open the node named NAME in the directory PARENT.  Set *CHILD_P to
 216    the new node, allocated in POOL.  NAME must be a single path
 217    component; it cannot be a slash-separated directory path.  */
 218 svn_error_t *svn_fs_fs__dag_open(dag_node_t **child_p,
 219                                  dag_node_t *parent,
 220                                  const char *name,
 221                                  apr_pool_t *pool);
 222
 223
 224 /* Set *ENTRIES_P to a hash table of NODE's entries.  The keys of the
 225    table are entry names, and the values are svn_fs_dirent_t's.  The
 226    returned table (and its keys and values) is allocated in POOL,
 227    which is also used for temporary allocations.  NODE_POOL is used
 228    for any allocation of memory that needs to live as long as NODE
 229    lives. */
 230 svn_error_t *svn_fs_fs__dag_dir_entries(apr_hash_t **entries_p,
 231                                         dag_node_t *node,
 232                                         apr_pool_t *pool,
 233                                         apr_pool_t *node_pool);
 234
 235
 236 /* Set ENTRY_NAME in NODE to point to ID (with kind KIND), allocating
 237    from POOL.  NODE must be a mutable directory.  ID can refer to a
 238    mutable or immutable node.  If ENTRY_NAME does not exist, it will
 239    be created.  TXN_ID is the Subversion transaction under which this
 240    occurs.*/
 241 svn_error_t *svn_fs_fs__dag_set_entry(dag_node_t *node,
 242                                       const char *entry_name,
 243                                       const svn_fs_id_t *id,
 244                                       svn_node_kind_t kind,
 245                                       const char *txn_id,
 246                                       apr_pool_t *pool);
 247
 248
 249 /* Make a new mutable clone of the node named NAME in PARENT, and
 250    adjust PARENT's directory entry to point to it, unless NAME in
 251    PARENT already refers to a mutable node.  In either case, set
 252    *CHILD_P to a reference to the new node, allocated in POOL.  PARENT
 253    must be mutable.  NAME must be a single path component; it cannot
 254    be a slash-separated directory path.  PARENT_PATH must be the
 255    canonicalized absolute path of the parent directory.
 256
 257    COPY_ID, if non-NULL, is a key into the `copies' table, and
 258    indicates that this new node is being created as the result of a
 259    copy operation, and specifically which operation that was.
 260
 261    PATH is the canonicalized absolute path at which this node is being
 262    created.
 263
 264    TXN_ID is the Subversion transaction under which this occurs.  */
 265 svn_error_t *svn_fs_fs__dag_clone_child(dag_node_t **child_p,
 266                                         dag_node_t *parent,
 267                                         const char *parent_path,
 268                                         const char *name,
 269                                         const char *copy_id,
 270                                         const char *txn_id,
 271                                         svn_boolean_t is_parent_copyroot,
 272                                         apr_pool_t *pool);
 273
 274
 275 /* Delete the directory entry named NAME from PARENT, allocating from
 276    POOL.  PARENT must be mutable.  NAME must be a single path
 277    component; it cannot be a slash-separated directory path.  If the
 278    node being deleted is a mutable directory, remove all mutable nodes
 279    reachable from it.  TXN_ID is the Subversion transaction under
 280    which this occurs.
 281
 282    If return SVN_ERR_FS_NO_SUCH_ENTRY, then there is no entry NAME in
 283    PARENT.  */
 284 svn_error_t *svn_fs_fs__dag_delete(dag_node_t *parent,
 285                                    const char *name,
 286                                    const char *txn_id,
 287                                    apr_pool_t *pool);
 288
 289
 290 /* Delete the node revision assigned to node ID from FS's `nodes'
 291    table, allocating from POOL.  Also delete any mutable
 292    representations and strings associated with that node revision.  ID
 293    may refer to a file or directory, which must be mutable.
 294
 295    NOTE: If ID represents a directory, and that directory has mutable
 296    children, you risk orphaning those children by leaving them
 297    dangling, disconnected from all DAG trees.  It is assumed that
 298    callers of this interface know what in the world they are doing.  */
 299 svn_error_t *svn_fs_fs__dag_remove_node(svn_fs_t *fs,
 300                                         const svn_fs_id_t *id,
 301                                         apr_pool_t *pool);
 302
 303
 304 /* Delete all mutable node revisions reachable from node ID, including
 305    ID itself, from FS's `nodes' table, allocating from POOL.  Also
 306    delete any mutable representations and strings associated with that
 307    node revision.  ID may refer to a file or directory, which may be
 308    mutable or immutable. */
 309 svn_error_t *svn_fs_fs__dag_delete_if_mutable(svn_fs_t *fs,
 310                                               const svn_fs_id_t *id,
 311                                               apr_pool_t *pool);
 312
 313
 314 /* Create a new mutable directory named NAME in PARENT.  Set *CHILD_P
 315    to a reference to the new node, allocated in POOL.  The new
 316    directory has no contents, and no properties.  PARENT must be
 317    mutable.  NAME must be a single path component; it cannot be a
 318    slash-separated directory path.  PARENT_PATH must be the
 319    canonicalized absolute path of the parent directory.  PARENT must
 320    not currently have an entry named NAME.  Do any temporary
 321    allocation in POOL.  TXN_ID is the Subversion transaction under
 322    which this occurs.  */
 323 svn_error_t *svn_fs_fs__dag_make_dir(dag_node_t **child_p,
 324                                      dag_node_t *parent,
 325                                      const char *parent_path,
 326                                      const char *name,
 327                                      const char *txn_id,
 328                                      apr_pool_t *pool);
 329
 330
 331 \f
 332 /* Files.  */
 333
 334
 335 /* Set *CONTENTS to a readable generic stream which yields the
 336    contents of FILE.  Allocate the stream in POOL.
 337
 338    If FILE is not a file, return SVN_ERR_FS_NOT_FILE.  */
 339 svn_error_t *svn_fs_fs__dag_get_contents(svn_stream_t **contents,
 340                                          dag_node_t *file,
 341                                          apr_pool_t *pool);
 342
 343
 344 /* Set *STREAM_P to a delta stream that will turn the contents of SOURCE into
 345    the contents of TARGET, allocated in POOL.  If SOURCE is null, the empty
 346    string will be used. */
 347 svn_error_t *
 348 svn_fs_fs__dag_get_file_delta_stream(svn_txdelta_stream_t **stream_p,
 349                                      dag_node_t *source,
 350                                      dag_node_t *target,
 351                                      apr_pool_t *pool);
 352
 353 /* Return a generic writable stream in *CONTENTS with which to set the
 354    contents of FILE.  Allocate the stream in POOL.
 355
 356    Any previous edits on the file will be deleted, and a new edit
 357    stream will be constructed.  */
 358 svn_error_t *svn_fs_fs__dag_get_edit_stream(svn_stream_t **contents,
 359                                             dag_node_t *file,
 360                                             apr_pool_t *pool);
 361
 362
 363 /* Signify the completion of edits to FILE made using the stream
 364    returned by svn_fs_fs__dag_get_edit_stream, allocating from POOL.
 365
 366    If CHECKSUM is non-null, it must match the checksum for FILE's
 367    contents (note: this is not recalculated, the recorded checksum is
 368    used), else the error SVN_ERR_CHECKSUM_MISMATCH is returned.
 369
 370    This operation is a no-op if no edits are present.  */
 371 svn_error_t *svn_fs_fs__dag_finalize_edits(dag_node_t *file,
 372                                            const char *checksum,
 373                                            apr_pool_t *pool);
 374
 375
 376 /* Set *LENGTH to the length of the contents of FILE, allocating from
 377    POOL. */
 378 svn_error_t *svn_fs_fs__dag_file_length(svn_filesize_t *length,
 379                                         dag_node_t *file,
 380                                         apr_pool_t *pool);
 381
 382 /* Put the recorded MD5 checksum of FILE into DIGEST, allocating from
 383  * POOL.  DIGEST must point to APR_MD5_DIGESTSIZE bytes of storage.
 384  *
 385  * If no stored checksum is available, do not calculate the checksum,
 386  * just put all 0's into DIGEST.
 387  */
 388 svn_error_t *
 389 svn_fs_fs__dag_file_checksum(unsigned char digest[],
 390                              dag_node_t *file,
 391                              apr_pool_t *pool);
 392
 393 /* Create a new mutable file named NAME in PARENT.  Set *CHILD_P to a
 394    reference to the new node, allocated in POOL.  The new file's
 395    contents are the empty string, and it has no properties.  PARENT
 396    must be mutable.  NAME must be a single path component; it cannot
 397    be a slash-separated directory path.  PARENT_PATH must be the
 398    canonicalized absolute path of the parent directory.  TXN_ID is the
 399    Subversion transaction under which this occurs.  */
 400 svn_error_t *svn_fs_fs__dag_make_file(dag_node_t **child_p,
 401                                       dag_node_t *parent,
 402                                       const char *parent_path,
 403                                       const char *name,
 404                                       const char *txn_id,
 405                                       apr_pool_t *pool);
 406
 407
 408 \f
 409 /* Copies */
 410
 411 /* Make ENTRY in TO_NODE be a copy of FROM_NODE, allocating from POOL.
 412    TO_NODE must be mutable.  TXN_ID is the Subversion transaction
 413    under which this occurs.
 414
 415    If PRESERVE_HISTORY is true, the new node will record that it was
 416    copied from FROM_PATH in FROM_REV; therefore, FROM_NODE should be
 417    the node found at FROM_PATH in FROM_REV, although this is not
 418    checked.  FROM_PATH should be canonicalized before being passed
 419    here.
 420
 421    If PRESERVE_HISTORY is false, FROM_PATH and FROM_REV are ignored.  */
 422 svn_error_t *svn_fs_fs__dag_copy(dag_node_t *to_node,
 423                                  const char *entry,
 424                                  dag_node_t *from_node,
 425                                  svn_boolean_t preserve_history,
 426                                  svn_revnum_t from_rev,
 427                                  const char *from_path,
 428                                  const char *txn_id,
 429                                  apr_pool_t *pool);
 430
 431 \f
 432 /* Comparison */
 433
 434 /* Find out what is the same between two nodes.
 435
 436    If PROPS_CHANGED is non-null, set *PROPS_CHANGED to 1 if the two
 437    nodes have different property lists, or to 0 if same.
 438
 439    If CONTENTS_CHANGED is non-null, set *CONTENTS_CHANGED to 1 if the
 440    two nodes have different contents, or to 0 if same.  For files,
 441    file contents are compared; for directories, the entries lists are
 442    compared.  If one is a file and the other is a directory, the one's
 443    contents will be compared to the other's entries list.  (Not
 444    terribly useful, I suppose, but that's the caller's business.)
 445
 446    ### todo: This function only compares rep keys at the moment.  This
 447    may leave us with a slight chance of a false positive, though I
 448    don't really see how that would happen in practice.  Nevertheless,
 449    it should probably be fixed.  */
 450 svn_error_t *svn_fs_fs__dag_things_different(svn_boolean_t *props_changed,
 451                                              svn_boolean_t *contents_changed,
 452                                              dag_node_t *node1,
 453                                              dag_node_t *node2,
 454                                              apr_pool_t *pool);
 455
 456
 457 /* Set *NODE_ID to the node-id of the coyproot of node NODE, or NULL
 458    if no copyroot exists.  Get any temporary allocations from POOL. */
 459 svn_error_t *svn_fs_fs__dag_get_copyroot(svn_revnum_t *rev,
 460                                          const char **path,
 461                                          dag_node_t *node,
 462                                          apr_pool_t *pool);
 463
 464 /* Set *REV to the copyfrom revision associated with NODE.  Get any
 465    temporary allocations from POOL. */
 466 svn_error_t *svn_fs_fs__dag_get_copyfrom_rev(svn_revnum_t *rev,
 467                                              dag_node_t *node,
 468                                              apr_pool_t *pool);
 469
 470 /* Set *PATH to the copyfrom path associated with NODE.  Get any
 471    temporary allocations from POOL. */
 472 svn_error_t *svn_fs_fs__dag_get_copyfrom_path(const char **path,
 473                                               dag_node_t *node,
 474                                               apr_pool_t *pool);
 475
 476 #ifdef __cplusplus
 477 }
 478 #endif /* __cplusplus */
 479
 480 #endif /* SVN_LIBSVN_FS_DAG_H */